1. Field of the Invention:
The present invention relates to a pulley drive system which is centrifugally clutched and furthermore may act as a centrifugally governed two speed drive, the same centrifugal mechanism being utilized for both clutching and varying the pulley drive ratios.
2. Description of the Prior Art:
Variable speed pulley drive systems and centrifugally governed clutches for pulleys are well known in the prior art. For instance, U.S. Pat. Nos. 3,715,930; 3,771,378; 3,659,470; and 3,812,731 disclose such variable speed centrifugally operated drive pulleys.
It is known in the art to utilize a multiple-speed clutch which is centrifugally controlled, such as the clutch disclosed in U.S. Pat. No. 3,159,257 assigned to the same assignee as this invention. This type of clutch has been used to vary the driven speed of mechanisms for clothes washers. Trigger released auxiliary weights and a speed selection mechanism to actuate the trigger for controlling the different speeds of these clutches is disclosed in U.S. Pat. No. 3,324,984, assigned to the same assignee at this invention.
It is also known in the prior art to utilize a belt drive for operating the transmission of a clothes washing machine. An example of such a belt drive is disclosed in U.S. Pat. No. 3,978,693 assigned to the same assignee as the present invention. Automatic clothes washing machines have at least two modes of operation, a washing mode and a spin mode. During the washing mode the vertical center post vaned structure or agitator is oscillated by means of a motor driven belt drive mechanism through a transmission. During the spin mode the agitator and basket containing the clothes are spun in unison at high speed to extract liquid from the clothes within the basket. In many cases it is desirable to provide two speeds of operation in these respective modes. In some cases this is obtained in the prior art by having the belt driven through a mechanism by a two speed motor and in others a two speed clutch mechanism is utilized. Such arrangements, however, are not entirely satisfactory.
By my invention I have improved the prior art pulley drive systems to provide a means for clutching and obtaining a two speed drive system particularly useful in clothes washing machines which is simple in construction, of low cost, has good regulation, and provides torque conversion to reduce the amount of energy used in obtaining the lower speed.